import exitHook from 'async-exit-hook'
import { Server } from 'http'
import { WebSocketServer } from 'ws'
import { Payload } from './payload'
import { stopInstance, watchers } from './registry-watcher'

let server: WebSocketServer

export const sendMessage = (message: Payload) => {
  if (!server) {
    return
  }
  const text = JSON.stringify(message)
  server.clients.forEach(client => {
    client.send(text)
  })
}
export const exitWebSocketServer = () => {
  if (!server) {
    return
  }
  sendMessage({ type: 'stop' })
  server.clients.forEach(c => c.close())
}
export const startWebSocketServer = (httpServer: Server) => new Promise<void>(resolve => {
  server = new WebSocketServer({ server: httpServer })
  server.on('connection', client => {
    sendMessage({ type: 'start', sessions: watchers.map(it => it.url) })
    client.on('message', data => {
      try {
        const payload: Payload = JSON.parse(data.toString())
        console.log('收到 DevClient 消息:', payload)
        switch (payload.type) {
          default: {
            break
          }
          case 'itemStop': {
            const { path } = payload
            const watcherIndex = watchers.findIndex(it => it.url === path)
            if (watcherIndex !== -1) {
              const [watcher] = watchers.splice(watcherIndex, 1)
              stopInstance(watcher.instance, () => {
                console.log(`功能编译器已退出: ${watcher.url}`)
              })
            }
            break
          }
          case 'querySessions': {
            sendMessage({ type: 'querySessionsResponse', sessions: watchers.map(it => it.url) })
            break
          }
        }
      } catch (error) {
        console.error('无效信息', data)
      }
    })
  })
  server.on('error', error => console.error(error))
  exitHook(exit => server.close(error => {
    if (error) {
      console.error(error)
    }
    exit()
  }))
  resolve()
})
